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St. Marys, ON
Your 2026 Fall Forecast is here!
Content continues below
September
Average Temperature
High
22°
Feels 22
Low
11°
Feels 10
Average Precipitation
9 Days
Rain amount
49.3mm
Snow amount
0cm
Content continues below
Daily Historical Averages
September 2026
S
M
T
W
T
F
S
1
2
3
4
5
6
7
8
9
10
22°
11
23°
12
24°
13
22°
14
19°
15
22°
16
22°
17
19°
18
18°
19
17°
20
17°
21
18°
22
18°
23
19°
24
19°
25
26
27
28
29
30
Forecast
Thursday, September 10, 2026
Day
22°
Feels 24
Wind
21 km/h NW
Gust
32 km/h
Humidity
57%
P.O.P
30%
Night
11°
Feels 11
Wind
15 km/h NE
Gust
23 km/h
Humidity
97%
P.O.P
30%
Historical Averages
Sep 10
High
Feels
Low
Feels
Precip Frequency
Total Daylight
Humidity
Historical Averages are based on data recorded from 2000 onwards.